Ratchet screwdriver type hand tool



July 11, 1967 B, aCNEILL 3,330,316

RATCHET SCREWDRIVER TYPE HAND TOOL Filed Feb. 21, 1966 v INVENTOR.

- H 4 I ARDEN B. MACNEILL ATTORNEY United States Patent 3,330,316RATCHET SCREWDRIVER TYPE HAN D TOOL Arden B. MacNeill, 63 Riverview Ava,Waltham, Mass. 07154 Filed Feb. 21, 1966, Ser. No. 538,499 6 Claims.(Cl. 145-72) This invention relates to ratchet screwdriver type handtools, and more particularly to an improved ratchet screwdriver typehand tool having compact and completely enclosed ratchet mechanism forinsuring long trouble free life and capable of heavy torque loading.

Use of hand tools, such as in connection with automobile servicing,often involves rough treatment in work loading as well as contactcontaminants such as road dirt on automobile components which tend toimpair operating mechanism in the tools. These problems have beenovercome in the present invention of a ratchet screwdriver type handtool which also incorporates other desirable features and advantages.Among these other desirable features and advantages is that ofstructural compactness for providing ease in use and storage. Otherdesirable features and advantages include that of selective right andleft hand torque operation through a simple rotative motion of anoperating cam about the tool axis itself, and a cam position providingfor locking the mechanism in place for both right and left hand torqueoperation with the single setting. Also, the present invention isconstructed with inherent capacity for inexpensive, high production linemanufacture and assembly for thereby meeting the requirements of a highquality tool at low cost.

A primary object of the present invention is the provision of animproved ratchet screwdriver type hand tool with completely inclosed,compact ratchet mechanism capable of selective right and left handtorque operation.

A further object is the provision of a ratchet screwdriver type handtool wherein the right and left hand torque operation may be selectedthrough the simple rotative movement of an operating cam about the axisof the tool itself.

A further object is the provision of a ratchet screwdriver type handtool wherein the operating cam has a position for locking the ratchetmechanism in place as a unitary structure for both right and left handtorque operation.

A still further object is the provision of a ratchet screwdriver typehand tool comprised of a relatively small number of components, all ofwhich have a configuration lending themselves to inexpensive highproduction manufacture and assembly for thereby providing a hi h qualitytool at low cost.

These and other features, objects and advantages are achieved generallyby the provision of an elongated member or shaft with two ends and alongitudinal axis located centrally thereof, a work engaging formationat one end, a handle at the other end, torque transmitting spacermembers fixed to the shaft adjacent the handle, a hollow ratchet wheelcarried by the torque transmitting members for rotation about the axisand having ratchet teeth about the internal periphery of the hollowwheel, a pawl mechanism fixed to the torque transmitting members withcapacity for pivoting into torque transmitting engagement with theratchet teeth, a hand operable structure for causing the pawl mechanismto selectively engage the ratchet teeth for torque transmission ineither left or right hand direction about the axis, and a leverextending from the hollow ratchet wheel in perpendicular relation to theaxis for applying torque to the ratchet wheel for transmission throughthe pawl mechanism, torque transmitting members and shaft to the workengaging formation.

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By making the pawl mechanism with a pair of pawl members mounted forpivotal movement outwardly in opposite directions from the axis so thatone of the pawls engages the ratchet teeth for torque transmission inone direction and the other pawl engages the ratchet teeth for torquetransmission in the opposite direction, a relatively simple arrangementfor right and left hand torque transmitting operation is therebyachieved.

By making the selective structure with a hand operable cam mounted onthe shaft for rotation about the axis and having a camming formation forselectively pivoting one or the other of the pawls in disengagedrelation to the ratchet teeth a readily accessible, convenient andsimple selective arrangement is thereby achieved.

By making the torque transmitting members as a series of thin discs andthe pawl members as a series of thin plates, inexpensive mass stampingproduction capability for said members is thereby achieved.

By making said camming member as a simple recessed structure andproviding tubular sleeve members for rigidly engaging the shaft at aswaged portion thereof, structures adaptable for sintered metalproduction and ease of assembly are thereby achieved.

These and other features, objects and advantages will be betterunderstood from the following description taken in connection with theaccompanying drawings of a preferred embodiment of the invention andwherein:

FIG. 1 is a partially side view and partially cutaway view of thepreferred embodiment and taken on line 11 of FIG. 2;

FIG. 2 is a cross sectional view to enlarged scale taken on line 22 ofFIG. 1;

FIG. 3 is a cross sectional view to enlarged scale taken on line 3-3 ofFIG. 1;

FIG. 4 is a cross sectional view to enlarged scale taken on line 44 ofFIG. 1.

Referring to the drawings in more detail, a ratchet screwdriver typehandle tool in accordance with the present invention is designatedgenerally by the numeral 10. The ratchet screwdriver type handtool illhas an elongated member or shaft 12 with a longitudinal axis 14 and awork engaging formation 16 at one end. A longitudinally swaged portionwith longitudinally extending ears 18 and 2%) are formed at the otherend of the shaft 12. In the present instance, the work engagingformation 16 is in the nature of a square cross section adapter carryinga conventional spring ball 22 for use with socket type tools such asdescribed and shown in my application for patent Serial No. 435,605filed February 26, 1965 and my application for patent Serial No. 444,957filed April 2, 1965. However, it should be understood that said workengaging formation 16 may also be directly, instead of an adapter, ascrewdriver tip or socket wrench or other desired configuration.

Fitted onto the bottom portion of the longitudinally extending swagedears 18 and 2t! and against a shoulder 2 formed with the shaft 12 is acollar 26 and a sleeve 28, each having an internal configuration to fitthe ears 1% and 2d and shaft 7.2. Rotatively mounted on the sleeve 28 isan operating cam structure 39 carrying internally thereof a circular camsurface 32 of a greater diameter than a second cam surface 34 separatedby a stop member 36 for purposes to be hereinafter further described.

Resting on the sleeve 28 are a series of thin torque transmittingmembers 38, each having a central opening similar to that of the sleeve28 for embracing the shaft 12 and ears 18 and 20 for integral movementwith the shaft 12. A spacer sleeve 40, similar to the sleeve 28, restson the torque transmitting members 33 and carries at its upper end afurther series of torque transmitting members 42 identical inconstruction to the torque transmitting members 38. A hollow ratchetwheel 44 is rotatively carried by the torque transmitting members 38 and42. The hollow ratchet wheel 44 has a lug extension 46 on its outerperiphery carrying a lever 48 having a knurled handle 50 and a threadedend 52 detachably screwed into a similarly threaded receptacle in thelug extension 46 so as to provide a manual torque applying lever 48substantially at right angles to the axis 14 of the shaft 12. The hollowratchet wheel 44 carries ratchet teeth 54 about the internal peripherythereof for receiving torque transmitting projections 56 and 58 on apair of pawls 60 and 62 respectively pivotally mounted on pivot pins 64and 68 anchored in the torque transmitting members 38 and 42. The pivotpins 64 and 68 permit the pawls 6i and 62 to swing inwardly toward theshaft 12 and outwardly toward the ratchet teeth 54 for engagement bytorque transmitting faces 61 and 63 of the torque transmittingprojections 56 and 58. The pawls 68 and 62 are normally urged outwardlytoward the ratchet teeth 54 by the fingers of a coil spring 70 mountedon a spring carrying pin 72. The torque transmitting faces 61 and 63 areat an angle such that when engaging the side of a ratchet tooth 54 inmanner shown by the torque transmitting face 63 in FIG. 2, the line offorce perpendicular to the torque transmitting face, such as face 63,will preferably pass through the center of the associated pivot, such aspivot 68, or slightly to the far side of the associated pivot pin, suchas to the right of pin 68, so as to prevent a disengaging rotationaltorque on the associated pawl, such as pawl 62, about the pivot Thepawls 68 and 62 also carry camming pins 74 and 76 respectively extendingthrough clearance holes 78 and 80 in the torque transmitting members 38and 42. The camming pins 74 and 76 extend downwardly into the cammingrecess of the rotatively mounted camming structure 30. When the cammingstructure is in the position shown in FIG. 4, the camming surface 34will cause the camming pin 74 to push the pawl 60 inwardly toward thespacer sleeve 40 so as to disengage the torque transmitting projection56 from the ratchet teeth 54. Also, in the position'shown in FIG. 4, thecamming pin 76 engages the camming surface 32 due to the pawl 62 beingurged outwardly by the coil spring 70 and causing the torquetransmitting extension 58 to engage the ratchet teeth 54. Thereby, inthe position of the operating cam 30 shown in FIG. 4, a clockwise torqueon the lever handle 50, as viewed in FIG. 2, will be transmitted throughthe torque transmitting projection 58, pawl 62, pivot pin 68, torquetransmitting members 38 and 42 to the shaft'12 and thereby the workengaging formation 16.

A handle 79, preferably of a plastic material, is carried on the shaft12 and conforms to longitudinally disposed ears 18 and 20 to form asubstantially integral structure with the shaft 12 for manual torquetransmission through the handle 79, the ears 18 and 20 and shaft 12 tothe work engaging formation 16.

In the operation of the present ratchet screwdriver type hand tool, asexplained above, when the rotatively mounted operating cam structure 30is in the position shown in FIG. 4, clockwise torque on lever handle 50is transmitted to the work engaging formation 16. Also, counterclockwiserotation of the lever 48 will cause the slant surface or back face 82 ofthe projection 58 to 'ride over the ratchet teeth 54 so'as to push thepawl 62 inwardly against the coil spring 70 without the transmission ofcounterclockwise torque to the work engaging formation 16. This permitsa backward and forward stroke motion of the lever 48 with only theforward or clockwise motion producing a torque to the work engagingformation 16.

When it is desired to produce a torque in a counter clockwise directionat the work engaging formation 16,

the rotatively mounted operating cam 30 is rotated counterclockwiseuntil the stop member 36 engages the camming pin 76. Thereby the cammingsurface 34 forces the camming pin 76 inwardly and carrying with it thepawl 62 inwardly toward the spacer sleeve 40 so as to disengage thetorque transmitting projection 58 from the ratchet teeth 54. At the sametime the camming surface 32, now at the camming pin 74, permits the pawl60 to swing outwardly so that the torque transmitting projection 56engages the side of ratchet tooth 54 for transmission ofcounterclockwise torque from the lever 48 through ratchet teeth 54,projection 56, pawl 60, pivot pin 64, torque transmitting members 38 and42, and shaft 12 to the work engaging formation 16. Also, in this newposition, a clockwise rotation of lever 48 will cause the slant surfaceor back face 84 of the projection 56 to ride over the ratchet teeth 54without the transmission of torque, thereby permitting short forward andbackward strokes of the lever 48 with only the backward orcounterclockwise strokes transmitting torque to the work engagingformation 16.

It has been found that by making the torque transmitting member 38 toclosely embrace the ears 18 and 20 on the shaft 12 for integral rotationwith the shaft 12 as explained above and of a width to provide aclearance 86 (FIG. 1) between the operating cam 30 and hollow ratchetwheel 44, the torque transmitting member 38 acts as a reaction washerfor isolating the operating cam 30 from torque effects and relativerotation of the hollow ratchet wheel 44 as from the lever handle 50.Thus, manual setting of the operating cam 30 remains undisturbedregardless of the above described relative rotary back and forth motionof the hollowratchet wheel 44 by lever 48.

It should be noted that the collar26, the sleeves 28 and 40 and thehollow ratchet wheel 44 together with the operating cam 30 are of asimple construction lend ing themselves to inexpensive sintered metalproduction.

Also, the multiple thin plate construction of the torque assembly fromthe hollow ratchet wheel 44 for convenient and compact storage of thehand tool, as in any conventional tool box.

It should be noted that by rotating the operating cam 30 'to anintermediate position wherein camming pins 74 and 76 both engage the camsurface 32, both pawls 60 and 62 are thereby permitted to engage ratchetteeth 54 for transmission of torque in both clockwise andcounterclockwise directions. The device thereby operates as a unitarystructure for those instances where it is desirable to eliminate theratchet action, as for example when the lever 48 is removed from theratchet wheel 44 and the remaining tool is used with the handle 78alone.

This invention is not limited to the particular details of constructionand operation described as equivalents will suggest themselves to thoseskilled in the art.

What I claim is: 1. In a ratchet screwdriver type hand tool, thecombination of a shaft with two ends and a longitudinal axis, a workengaging formation at one of said ends, a handle at the other of saidends, torque transmitting members fixed to said shaft adjacent saidhandle, a hollow ratchet wheel rotatably carried by said torquetransmitting members for rotation about said axis and having ratchetteeth about the internal periphery of said hollow wheel, a pawlmechanism fixed to said torque transmitting members with capacity forpivoting into torque transmitting engagement with said ratchet teeth,hand operable means for causing said pawl mechanism to selectivelyengage said ratchet teeth for torque transmission in either directionabout said axis, and a lever extending from said hollow ratchet wheel inperpendicular relation to said axis for applying torque to said ratchetwheel for transmission through said pawl mechanism, torque transmittingmember and shaft to said Work engaging formation.

2. The combination as in claim 1 wherein said pawl mechanism includes apair of pawl members mounted to said torque transmitting members forpivotal movement outwardly in opposite directions from said axis so thatone of said pawls engages said ratchet teeth for torque transmission inone direction and the other pawl engages said ratchet teeth in torquetransmitting engagement in the opposite direction.

3. The combination as in claim 2 wherein said hand operable meansincludes a hand operable cam mounted on said shaft for rotation aboutsaid axis and having a camming formation for selectively pivoting oneand the other of said pawls in disengaged relation from said ratchetteeth.

4. The combination as in claim 2 wherein said torque transmittingmembers and pawls are of a plurality of thin plate-like elements.

5. The combination as in claim 3 wherein the torque transmitting memberadjacent the operating cam embraces said shaft for integralrotation withsaid shaft about said axis, and having a width providing a clearancebetween said hand operable cam and hollow ratchet wheel for therebyisolating said cam from relative rotational influences of said hollowratchet wheel.

6. The combination as in claim 3 wherein said hollow ratchet wheel andhand operable cam are of sintered metal.

References Cited UNITED STATES PATENTS 1,258,582 3/1918 McGuiTey 81-612,732,049 1/1956 De Liso 81-62 X 2,778,396 l/ 1957 Swain. 3,256,9666/1966 Angquist 81-62 X WILLIAM FELDMAN, Primary Examiner.

R. V. PARKER, JR., Assistant Examiner.

1. IN A RATCHET SCREWDRIVER TYPE HAND TOOL, THE COMBINATION OF A SHAFTWITH TWO ENDS AND A LONGITUDINAL AXIS, A WORK ENGAGING FORMATION AT ONEOF SAID ENDS, A HANDLE AT THE OTHER OF SAID ENDS, TORQUE TRANSMITTINGMEMBERS FIXED TO SAID SHAFT ADJACENT SAID HANDLE, A HOLLOW RATCHET WHEELROTATABLY CARRIED BY SAID TORQUE TRANSMITTING MEMBERS FOR ROTATION ABOUTSAID AXIS AND HAVING RATCHET TEETH ABOUT THE INTERNAL PERIPHERY OF SAIDHOLLOW WHEEL, A PAWL MECHANISM FIXED TO SAID TORQUE TRANSMITTING MEMBERSWITH CAPACITY FOR PIVOTING INTO TORQUE TRANSMITTING ENGAGEMENT WITH SAIDRATCHET TEETH, HAND OPERABLE MEANS FOR CAUSING SAID PAWL MECHANISM TOSELECTIVELY ENGAGE SAID RATCHET TEETH FOR TORQUE TRANSMISSION IN EITHERDIRECTION ABOUT SAID AXIS, AND A LEVER EXTENDING FROM SAID HOLLOWRATCHET WHEEL IN PERPENDICULAR RELATION TO SAID AXIS FOR APPLYING TORQUETO SAID RATCHET WHEEL FOR TRANSMISSION THROUGH SAID PAWL MECHANISM,TORQUE TRANSMITTING MEMBER AND SHAFT TO SAID WORK ENGAGING FORMATION.